Optimization of CCOs with Implantable MEMS Pressure Sensors for Cardiovascular Applications

2019 ◽  
Author(s):  
Jose Angel Miguel ◽  
Yolanda Lechuga ◽  
Miguel Angel Allende ◽  
Mar Martinez
Keyword(s):  
Pressure Sensors ◽  
Mems Pressure Sensors

scholarly journals Dynamic flight load measurements with MEMS pressure sensors

2021 ◽  
Author(s):  
Christian Raab ◽  
Kai Rohde-Brandenburger
Keyword(s):  
Pressure Distribution ◽  
Pressure Sensors ◽  
Flow Characteristics ◽  
Flight Test ◽  
Measurement Technology ◽  
Test Program ◽  
Aerodynamic Pressure ◽  
Pressure Distributions ◽  
Time Histories ◽  
Mems Pressure Sensors

AbstractThe determination of structural loads plays an important role in the certification process of new aircraft. Strain gauges are usually used to measure and monitor the structural loads encountered during the flight test program. However, a time-consuming wiring and calibration process is required to determine the forces and moments from the measured strains. Sensors based on MEMS provide an alternative way to determine loads from the measured aerodynamic pressure distribution around the structural component. Flight tests were performed with a research glider aircraft to investigate the flight loads determined with the strain based and the pressure based measurement technology. A wing glove equipped with 64 MEMS pressure sensors was developed for measuring the pressure distribution around a selected wing section. The wing shear force determined with both load determination methods were compared to each other. Several flight maneuvers with varying loads were performed during the flight test program. This paper concentrates on the evaluation of dynamic flight maneuvers including Stalls and Pull-Up Push-Over maneuvers. The effects of changes in the aerodynamic flow characteristics during the maneuver could be detected directly with the pressure sensors based on MEMS. Time histories of the measured pressure distributions and the wing shear forces are presented and discussed.

Comparison of hermetic sealing using SAC and SnPb solder for a MEMS pressure sensor

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 000464-000487
Author(s):  
Maaike M. Visser Taklo ◽  
Branson Belle ◽  
Joachim Seland Graff ◽  
Astrid-Sofie Vardøy ◽  
Elisabeth Ramsdal
Keyword(s):  
Cross Sections ◽  
Pressure Sensors ◽  
Thick Layer ◽  
Long Term Effects ◽  
Soldering Process ◽  
Long Term Stability ◽  
Hermetic Seal ◽  
Reduced Rate ◽  
Mems Pressure Sensors

In order to minimize the influence of packaging stress on the signal of MEMS pressure sensors, the pressure inlet can be reduced in footprint and mechanically decoupled from the mechanically moving parts. Moreover, the formation of a hermetic seal between the sensor inlet and an external inlet becomes more challenging as the footprint is reduced. Soldering is a preferred solution as a hermetic seal is achievable despite some surface roughness at the surfaces to be joined. However, the metallization on the MEMS, the solder and the metallization on the external inlet must be carefully matched to assure long term stability; the solder will react quickly with the metal layers deposited on the surfaces during the reflow process and later at a reduced rate during storage and application. The formation of intermetallic compounds (IMC) can catastrophically degrade the integrity of a joint if large amounts of voids are formed or the mechanical compliance significantly reduces as a result of the IMC formation. The metallization alternatives for the MEMS in this case were sputtered TiW/Au and NiCr/Au. The TiW and NiCr are adhesion layers whereas the Au is applied as a wetting layer which is normally fully consumed during the soldering process. A thick layer of plated Au, or a thick layer of plated Ni with a thin surface finish layer of Au, were possible metallization alternatives for the external inlet. Dewetting of solder from TiW is frequently mentioned in literature, but less conclusive work is published about soldering to NiCr/Au [1–3]. In particular, limited work has been published on long term effects of soldering to NiCr/Au surfaces using a SAC solder. In this work TiW and NiCr were compared as adhesion layers. In addition, SAC and SnPb were compared as solder, and Au and Ni/Au were compared as metallization on the external inlet. A total of 10–20 assemblies were prepared for each of 12 tested combinations. Half of the assemblies were exposed to high temperature storage (HTS) for ~300 hours at 130–150 °C. Shear testing and inspection of fracture surfaces and cross sections using light microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were performed for samples

Internal and external factors effect on the mobile pressure sensors’ performance

Sensor Review ◽  
2016 ◽  
Vol 36 (4) ◽  
pp. 405-413 ◽  
Author(s):  
Semih Dalgin ◽  
Ahmet Özgür Dogru
Keyword(s):  
Pressure Sensor ◽  
Mobile Applications ◽  
Pressure Sensors ◽  
External Factors ◽  
Sensor Data ◽  
High Tech ◽  
Internal Factors ◽  
Content Type ◽  
Internal And External Factors ◽  
Mems Pressure Sensors

Purpose The purpose of this study is to investigate the effect of internal and external factors on the accuracy and consistency of the data provided by mobile-embedded micro-electromechanical system (MEMS) pressure sensors based on smartphones currently in use. Design/methodology/approach For this purpose, sensor type and smartphone model have been regarded as internal factors, whereas temperature, location and usage habits have been considered as external factors. These factors have been investigated by examining data sets provided by sensors from 14 different smartphones. In this context, internal factors have been analyzed by implementing accuracy assessment processes for three different smartphone models, whereas external factors have been evaluated by analyzing the line charts which present timely pressure changes. Findings The study outlined that the sensor data at different sources have different characteristics due to the affecting parameters. Even if the pressure sensors are used under similar circumstances, data of these sensors have inconsistencies because of the sensor drift originated by internal factors. This study concluded that it was not applicable to provide a common correction coefficient for pressure sensor data of each smartphone model. Therefore, relative data (pressure differences) should be taken into consideration rather than absolute data (pressure values) when developing mobile applications using sensor data. Research limitations/implications Results of this study can be used as the guideline for developing mobile applications using MEMS pressure sensors. One of the main finding of this paper is promoting the use of relative data (pressure differences) rather than absolute data (pressure values) when developing mobile applications using smartphone-embedded sensor data. This significant result was proved by examinations applied with in the study and can be applied by future research studies. Originality/value Existing studies mostly evaluate the use of MEMS pressure sensor data obtained from limited number of smartphone models. As each smartphone model has a specific technology, factors affecting the sensor performances should be identified and analyzed precisely in terms of smartphone models for providing extensive results. In this study, five smartphone models were used fractionally. In this context, they were used for examining the common effects of the factors, and detailed accuracy assessments were applied by using two high-tech smartphones in the market.

Effects of biomedical sterilization processes on performance characteristics of MEMS pressure sensors

2007 ◽  
Vol 9 (6) ◽  
pp. 809-814 ◽  
Author(s):  
L. A. Ferrara ◽  
A. J. Fleischman ◽  
J. L. Dunning ◽  
C. A. Zorman ◽  
S. Roy
Keyword(s):  
Pressure Sensors ◽  
Performance Characteristics ◽  
Mems Pressure Sensors

A pressure-deformation analytical model for rectangular diaphragm of MEMS pressure sensors

2017 ◽  
Vol 31 (05) ◽  
pp. 1750046
Author(s):  
Wu Zhou ◽  
Dong Wang ◽  
Huijun Yu ◽  
Bei Peng
Keyword(s):  
Pressure Sensor ◽  
Applied Pressure ◽  
Influence Factors ◽  
Pressure Sensors ◽  
Superposition Method ◽  
Uniform Load ◽  
Pressure Sensitive ◽  
Partial Load ◽  
Mems Pressure Sensors ◽  
Measured Pressure

Rectangular diaphragm is commonly used as a pressure sensitive component in MEMS pressure sensors. Its deformation under applied pressure directly determines the performance of micro-devices, accurately acquiring the pressure–deflection relationship, therefore, plays a significant role in pressure sensor design. This paper analyzes the deflection of an isotropic rectangular diaphragm under combined effects of loads. The model is regarded as a clamped plate with full surface uniform load and partially uniform load applied on its opposite sides. The full surface uniform load stands for the external measured pressure. The partial load is used to approximate the opposite reaction of the silicon island which is planted on the diaphragm to amplify the deformation displacement, thus to improve the sensitivity of the pressure sensor. Superposition method is proposed to calculate the diaphragm deflections. This method considers separately the actions of loads applied on the simple supported plate and moments distributed on edges. Considering the boundary condition of all edges clamped, the moments are constructed to eliminate the boundary rotations caused by lateral load. The diaphragm’s deflection is computed by superposing deflections which produced by loads applied on the simple supported plate and moments distributed on edges. This method provides higher calculation accuracy than Galerkin variational method, and it is used to analyze the influence factors of the diaphragm’s deflection, includes aspect ratio, thickness and the applied force area of the diaphragm.

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